In the construction industry, delays are inevitable. However, when more than one party contributes to those delays, the question becomes: who bears the risk? Jurisdictions vary widely in how they treat concurrent delay, apportionment, and causation doctrines such as the “first-in-time” and “dominant cause” approaches. This article outlines how these doctrines are applied across key jurisdictions relevant to international projects: the UK, UAE/KSA, Turkiye, the USA, Scotland, and selected civil law jurisdictions in continental Europe (including Romania, Serbia, Georgia, and Moldova).
1. Concurrent Delay
Definition: Occurs when delays caused by two or more parties overlap in time and affect the critical path.
The SCL Protocol defines concurrency as: “True concurrent delay is the occurrence of two or more delay events at the same time, one an Employer Risk Event, the other a Contractor Risk Event, and the effects of which are felt at the same time. For concurrent delay to exist, each of the Employer Risk Event and the Contractor Risk Event must be an effective cause of Delay to Completion (i.e. the delays must both affect the critical path). Where Contractor Delay to Completion occurs or has an effect concurrently with Employer Delay to Completion, the Contractor’s concurrent delay should not reduce any EOT due.”
- UK: Concurrent delays are well-established. Courts typically allow the contractor time (EOT) but not compensation for concurrent delays (Malmaison principle, Henry Boot v Malmaison Hotel [1999]). True concurrency does not require delays to start and finish on the same day—partial overlaps may suffice (Walter Lilly v Mackay [2012], Saga Cruises BDF Ltd v Fincantieri SPA [2016]).
- UAE/KSA: No formal doctrine in codified law, but arbitration practice accepts concurrency, especially in FIDIC-based contracts. Courts focus more on causation and fault. In arbitration, partial overlaps are frequently accepted as concurrent.
- Turkiye: Similar to civil law jurisdictions; concurrency is not clearly defined in law, but FIDIC-influenced practice allows it. Courts focus on causation and may require expert evidence.
- USA: Concurrent delay is broadly defined and widely accepted in both federal and state jurisdictions. Courts and boards typically require that the delays overlap in time and affect the critical path. True concurrency does not require identical start and finish dates (Blinderman Construction v U.S. [1982], Essex Electro Engineers).
- Scotland: Recognizes concurrency, and unlike England, apportionment may be accepted. The City Inn v Shepherd Construction [2003] case accepted concurrency based on overlapping impacts rather than precise simultaneity.
- Continental Europe (Romania, Serbia, Georgia, Moldova): Concurrency is not a codified concept. Delay is analyzed through causation and proportional fault. Partial overlaps can be considered if the impact is demonstrated.
Note: There are conceptual parallels between Scottish and continental European legal thinking. Although Scotland follows a mixed legal tradition with civil law roots, its pragmatic application of concurrency and apportionment, as seen in City Inn, resonates with the fault-based, equitable approach found in civil law jurisdictions across Europe. While civil law systems lack a formal concurrency doctrine, their courts often rely on proximate causation, contributory negligence, and proportional responsibility—principles closely aligned with the spirit, if not the structure, of Scots law.
2. Apportionment
Definition: Allocation of delay responsibility between parties based on their relative contributions.
- UK: Generally not permitted. The prevailing approach grants full EOT but denies costs if there is true concurrency which does not require delays to start and finish on the same day.
- UAE/KSA: Increasingly accepted in arbitration. Courts may not apply it expressly but arbitrators often apportion delay responsibility (e.g., 60/40 or 50/50).
- Turkiye: Apportionment is not part of formal law but can be considered under equitable principles or through expert determination in arbitration.
- USA: Accepted and commonly applied, particularly in federal contracts. Boards and courts may apportion time or cost responsibility when the contractor and owner both contribute to the delay (Mennonite Board of Missions v. United States,
60 Fed. Cl. 292 (2004)). - Scotland: Courts may apportion both time and costs when multiple causes are found. City Inn confirmed that where concurrent delays exist, judges may apply a discretionary apportionment.
- Continental Europe: Apportionment aligns well with civil law systems’ emphasis on contributory fault. It is often used to allocate liability and damages proportionally.
3. First-in-Time Approach
Definition: Prioritizes the delay that occurred first, potentially negating the effect of later delays.
- UK: Rarely determinative. Courts prefer critical path and concurrent delay analyses.
- UAE/KSA: May be applied in court to identify primary responsibility, especially in absence of formal concurrency doctrine.
- Turkiye: Courts may favor early delay events in attributing liability, especially if one party’s fault clearly predates the other’s.
- USA: Frequently applied. If the contractor delay starts earlier and remains on the critical path, government-caused delays may be deemed non-compensable (Triax Pacific v Stone [1992]).
- Scotland: The court may consider timing, but not as a standalone basis. Relative importance and causation prevail.
- Continental Europe: Frequently used to determine causality. The earlier breach or obstruction is often deemed more significant.
4. Dominant Cause Approach
Definition: Focuses on the most significant or operative cause among multiple contributing events.
- UK: Recognized but rarely overrides concurrency where both delays are critical. Courts look for the most impactful cause if no true concurrency exists.
- UAE/KSA: Strongly aligned with dominant cause reasoning, especially in courts where causation drives liability.
- Turkiye: Dominant cause analysis is acceptable in expert reports and legal reasoning, especially in mixed-fault scenarios.
- USA: Common in delay claims. Courts may deny recovery if the contractor’s fault is the dominant or continuing cause of delay (George Sollitt Construction v U.S. [2005]).
- Scotland: Courts apply this approach pragmatically. City Inn factored in the relative weight and impact of causes when apportioning responsibility.
- Continental Europe: Fully compatible with civil law tradition. Courts aim to identify the proximate cause based on fault and impact.
Conclusion
While concurrent delay and apportionment are increasingly accepted in international arbitration, national courts—particularly in civil law jurisdictions—still prioritize causation and dominant liability. The trend in common law jurisdictions such as the USA and Scotland shows more flexibility, with courts willing to assess overlapping delays even where start and end dates differ. Moreover, the Scottish approach in City Inn—which balances overlapping causation with equitable apportionment—echoes the causation-based reasoning common in civil law systems. Understanding how different jurisdictions interpret overlapping delays is crucial for claim strategists and contract professionals. Whether you’re drafting an EOT claim or defending against prolongation costs, tailoring your legal argument to the governing law and local judicial culture can make a decisive difference. A comparative overview of the various jurisdictions is set out below:
| Jurisdiction | True Concurrency | Apportionment | First-in-time Approach | Dominant Cause Approach |
| United Kingdom | partial overlaps may suffice | not accepted | rarely determinative | recognized if no true concurrency |
| UAE/KSA | recognized | accepted in arbitration | may be applied | strongly aligned |
| Turkiye | recognized | depends | frequently applied | depends on mixed-fault scenarios |
| USA | recognized | accepted in many forums | frequently applied | widely accepted in delay claims |
| Scotland | recognized | accepted on courts | depends on timing | applied pragmatically |
| Continental Europe | recognized | depends | frequently applied | fully compatible with civil law |
Table 1: Comparative Overview
